Technologies are described for generating, acquiring, transferring, and manipulating sets of interaction representations, where an interaction representation represents user interaction with content on a computer device, typically using a software application. The set can be represented as an interaction representation. To facilitate set creation, including adding items to a set, a request can be sent to an application to provide an interaction representation, such as an interaction representation of a current state of user-content interaction associated with the software application. Sets can be associated with different types, where the set type can determine whether, and what types, of interaction representations can be added to a set. Sets can be associated with expiration events, where the interaction representation for the set, and in some cases the component interaction representations, can be deleted upon the occurrence of the expiration event. In some cases, a set can be designated not to expire.